If you thought NSA's PRISM system was invasive to your privacy, just wait until you hear what the National Taiwan University team has been up to. Lead by Hao-hua Chu, they've just tested prototypes of a new tooth sensor that is capable of detecting if you're smoking or overeating.

The team tested them in eight people's dentures, with the sensor featuring accelerometers that are capable of detecting the difference between chewing, smoking, speaking and coughing, roughly 94% of the time. It can only get better, with next-gen versions possibly detecting the type of food you're eating, which would be a huge step for health.

The biggest issue is scientists first have to create an on-power power source, as the prototypes currently run from external batteries, and secondly mouth-safe Bluetooth connectivity so that it can transmit data to smartphones. The team are already talking about shrinking the tooth sensor down so that it could fit inside cavities or crowns.